Pull-ups and chin-ups are a popular form of exercise performed with a pull-up (or chin-up) bar. Other exercises can be performed with this device as well. Typically for a novice, however, a pull-up or a chin-up can be difficult to do, thus requiring assistance. Additionally, for an experienced person, a pull-up or a chin-up can become relatively easy to do, thus requiring resistance. The present invention features a versatile doorway exercise system using a pull-up bar while adding assistance or resistance as desired.